Weak HashSet from objectweb jac : Weak Set « Collections Data Structure « Java

Weak HashSet from objectweb jac

// Revised from objectweb jac

import java.lang.Cloneable;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import java.util.WeakHashMap;

public class WeakHashSet extends AbstractSet
    implements Set
    private transient WeakHashMap map;

    public WeakHashSet() {
        map = new WeakHashMap();
    public WeakHashSet(Collection c) {
        map = new WeakHashMap(Math.max((int) (c.size()/.75f) + 1, 16));
    public WeakHashSet(int initialCapacity, float loadFactor) {
        map = new WeakHashMap(initialCapacity, loadFactor);
    public WeakHashSet(int initialCapacity) {
        map = new WeakHashMap(initialCapacity);

    public Iterator iterator() {
        return map.keySet().iterator();

    public int size() {
        return map.size();
    public boolean isEmpty() {
        return map.isEmpty();

    public boolean contains(Object o) {
        return map.containsKey(o);

    public boolean add(Object o) {
        return map.put(o, Boolean.TRUE)==null;
    public boolean remove(Object o) {
        return map.remove(o)==Boolean.TRUE;
    public void clear() {


Related examples in the same category

1.Weak HashSet
2.Weak HashSet from TJDO
3.Set which holds its members by using of WeakReferences.
4.A weak HashSet: element stored in the WeakHashSet might be garbage collected